1. Field of the Invention
The present invention relates to a recording medium transfer apparatus. More particularly, the present invention relates to a recording medium transfer apparatus for transferring a recording medium on which recording or printing is performed by ejecting liquid to a liquid ejection area where the liquid is ejected onto the recording medium.
2. Description of the Related Art
A liquid ejecting apparatus such as an inkjet type recording apparatus includes a recording medium transfer apparatus. In order to improve the recording throughput of the liquid ejecting apparatus, it is effective to increase the speed of transferring the recording medium by the recording medium transfer apparatus. However,the transfer speed of the recording medium is restricted depending on the operation state of the liquid ejecting apparatus.
When many recording mediums are discharged, it is necessary to obtain the stackability by which the discharged recording mediums are stacked at approximately the same position on a discharge stacker. In order to obtain the stackability, the discharge speed at which the discharge roller discharges the recording mediums to the discharge stacker is necessarily restricted to a specific value or less, e.g. 10[ips] (inch per second). If the discharge speed of the recording medium exceeds the specific value, the electrostatic force caused by electrification of the recording medium mainly decreases the stackability. Meanwhile, when the recording medium is fed to the liquid ejection area where liquid is ejected onto the recording medium, in order to increase the throughput, it is preferable that the feed roller should transfer the recording medium at higher speed, e.g. 14[ips], than the discharge roller during discharge.
For the purpose of cost-down, a technology in which the liquid ejecting apparatus drives both the discharge roller for discharging the recording medium on which recording has been finished and the feed roller for feeding the next recording medium by one motor has been recently developed as disclosed, for example, in Japanese Patent Application Publication No. 2002-283649.
If the discharge and feed rollers are driven by one motor, both the rollers rotate at the same speed. In this case, when the rotation speed of the feed roller becomes high to improve the throughput, the rotation speed of the discharge roller also becomes high, so there is such a problem that the stackability cannot be obtained.